MORNING VS. EVENING TRAINING
When considering the best time of day to train, surely individual preferences are involved. Some early birds are more drawn to the morning run, while other night owls prefer the evening run. But is one time of day more optimal for training? Does the timing really matter from a performance perspective? Let’s take a look at the benefits and drawbacks of each.
Morning training:
Whether training for a fast 5k or a marathon, consistency is crucial for long-term progression and performance gains. And like investing in the stock market, consistency in training compounds over time and enables massive progress over months and years of training. The morning run provides consistency and routine, which is crucial for establishing behavior change or habit formation.
There are plenty of barriers to becoming consistent with any exercise or health-related endeavor. External factors might include time constraints, social or work-related events that disrupt your plans to go for a run. Internal factors include self-motivation, discipline, and choosing to stick to a routine or training schedule even on days where you don’t want to.
For most people the morning time has fewer external barriers, less distractions or life constraints (ie. social or work-related events), and therefore the likelihood of “life getting in the way” of training is low. Sure, there are some mornings where you might be more tired than others and it can be difficult to find the internal motivation to crawl out of your warm, cozy bed. But there is less likelihood of external factors disrupting your intentions to go for a run. If you’re looking to establish a consistent and repeatable routine of running, wake up and train in the morning.
Additional benefits to morning training include improved sleep, hormonal benefits, and metabolic advantages. Research suggests that a morning exercise habit can shift your circadian rhythm over time, making your body more alert in the morning and more tired in the evening. Morning exercise also seems to promote deep sleep without the likelihood of disrupting your body’s natural rhythm of winding down at the end of the day, allowing you to find more restful sleep.
When running in the morning, often you will be training in a fasted state and without having eaten in >8 hours. Exercising on an empty stomach burns more fat than exercising after a meal, training the body to utilize fat oxidation when running at low intensities (about 60-70% of max heart rate). This can be beneficial for endurance runners looking to increase their fat-burning efficiency, especially if training for a longer event.
Training in the morning will also provide a psychological boost, setting a positive tone for the rest of the day. This is especially the case if you’re able to mix-up the pace of your run, and complete the morning run as the sun begins to bring daylight. As mentioned in a previous post on How Running Changes Your Brain, exercise stimulates the release of brain-derived neurotrophic factor (BDNF) which promotes increased alertness, mental clarity, and focus.
The drawbacks of morning training lie in the performance realm. Because morning runs are often completed in a fasted state, your body is running on low fuel and will not express peak performance. Not only are the body’s glucose supplies low, but the body also becomes dehydrated overnight. One way to mitigate this negative effect is to drink a glass of water first thing after waking up, prior to lacing up the shoes and running.
Evening training:
If I haven’t given myself away yet, I’ll admit I have my own bias as a routine morning runner. But there are certainly some perks to training later in the day. The body’s internal clock or Circadian Rhythm influences fluctuations in various physiological processes, which can have a significant impact on performance and training. Blood pressure and core body temperature increases later in the day, and with it one may experience heightened alertness, reaction time, and maximal force production in comparison to morning times. This can improve running performance especially if performing interval or threshold workouts.
Additionally the muscles and joints are often more flexible and warmed up in the afternoon and evening time, reducing risk of injury especially during high intensity efforts. At this time of day, fuel stores in the body are adequately supplied from meals throughout the day which provides more readily available energy for performance while reducing any risk of depletion during the workout.
A study in Chronobiology International found that athletes who trained in the evening had better performance in high-intensity activities, likely due to the body's circadian rhythms, which favor physical exertion in the late afternoon to early evening. Some studies even suggest that exercise in the evening can lead to better sleep quality, which is crucial for recovery, as long as the training does not run too close to bedtime.
Sleep interference is one potential downside of training in the evening, especially if the evening session is a high-intensity effort. Interval sessions or threshold runs will raise cortisol levels at the end of the day, which can shift your sleep/wake cycle and make it more difficult to wind down in the evening. If you choose to workout in the evening, aim to complete the workout at least two hours prior to your target bedtime.
Another downside to training in the evening is consistency. In the mornings the greatest hurdle to running is intrinsic motivation and getting out of bed, but in the evening there are more external factors that can get in the way. Accumulated fatigue from a long day can negatively impact evening training sessions, and other responsibilities might disrupt a training schedule at this time of day.
The optimal time to train for running, whether in the morning or evening, can vary depending on several factors, including individual physiology, goals, and lifestyle. Research and evidence-based material suggest that both times have their pros and cons from a performance perspective.
The verdict:
Personally, I enjoy a daily morning run. Most of these daily runs are done in a fasted state and at an easy effort, a “conversational” pace run. If I plan to do an interval workout or a threshold session, I will consume a light snack and implement a longer dynamic warm up prior to any quality training to ensure my body is prepared for the effort. Occasionally I will run doubles with an easy run in the morning and a hard workout in the evening, as I have noticed my legs can turnover quicker later in the day.
Ultimately the best time to train depends on individual preferences, your personal schedule, and how your body responds to training at different times of day. Consider the pros and cons of training in the morning versus the evening, and you may be able to optimize a routine that works best for you. Consistency is the key ingredient to success in running (or any other endeavor). Therefore the best time of day to run is the time of day when you can establish a routine.
